Cutting assembly for surgical instrument with clog reducing tip

ABSTRACT

A cutting assembly for a surgical instrument. A tube assembly includes an outer tube having an outer cutting window, and an inner tube coaxially disposed within and rotatable relative to the outer tube. The inner tube includes an inner cutting window such that the inner and outer cutting windows define a cutting window of the tube assembly. A portion of the inner tube distal a proximal boundary of the cutting window may define a distal region of the inner tube. A projection is within a lumen of the inner tube with at least a portion of the projection disposed within the distal region. The projection may be an insert. The projection occupies a volume of the distal region and/or reduces a cross-sectional area of the lumen distal to the proximal boundary. The projection reduces the size of material removed through the cutting window to reduce clogging of the tube assembly.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a U.S. National Stage of International PatentApplication No. PCT/US2017/042101, filed on Jul. 14, 2017, which claimspriority to and all the benefits of U.S. Provisional Patent ApplicationNo. 62/362,117, filed on Jul. 14, 2016, the entire contents of each arehereby incorporated by reference.

TECHNICAL FIELD

The present disclosure relates generally to surgical instruments and,more particularly to, a surgical instrument with a clog reducing tip foruse on patients.

BACKGROUND

It is known that medical practitioners have found it useful to usesurgical instruments to assist in the performance of surgicalprocedures. A surgical instrument is designed to be applied to asurgical site on the patient. The practitioner is able to position thesurgical instrument at the site on the patient at which the instrumentis to perform a medical or surgical procedure. Endoscopic surgicalprocedures are routinely performed in order to accomplish varioussurgical tasks. In an endoscopic surgical procedure, small incisions,called portals, are made in the patient. An endoscope, which is a devicethat allows medical personnel to view the surgical site, is inserted inone of the portals. Surgical instruments used to perform specificsurgical tasks are inserted into other portals. The surgeon views thesurgical site through the endoscope to determine how to manipulate thesurgical instruments in order to accomplish the surgical procedure. Anadvantage of performing endoscopic surgery is that, since the portionsof the body that are cut open are minimized, the portions of the bodythat need to heal after surgery are likewise reduced. Moreover, duringan endoscopic surgical procedure, only relatively small portions of thepatient's internal organs and tissue are exposed to the openenvironment. This minimal opening of the patient's body lessens theextent to which a patient's organs and tissue are open to infection.

Many tube devices have been developed for use in surgical procedures.They are valuable because they facilitate reduced incision size,improved access and visibility, while enhancing surgical outcome andquicker recovery. Some are cutting devices having either two tubes, onewithin another, or a single tube with a cutting window. Such cuttingdevices may be an ear, nose, and throat (ENT) shaver devices.

Clogging of ENT shaver devices is a common annoyance during endoscopicsinus surgery. A common cause of clogging is the trapping of sinus boneand tissue at the distal tip of the ENT shaver device just proximal of acutting window. Another common cause of clogging is the trapping ofsinus bone and tissue just proximal the tube(s) of the cutting device.

A surgical instrument that overcomes these challenges is desired.

BRIEF DESCRIPTION OF THE DRAWINGS

Advantages of the present disclosure will be readily appreciated as thesame becomes better understood by reference to the following detaileddescription when considered in connection with the accompanyingdrawings.

FIG. 1 is a perspective view of a surgical instrument according to anexemplary embodiment of the present disclosure.

FIG. 2 is an exploded perspective view of the surgical instrument ofFIG. 1 with a drive assembly removed.

FIG. 3 is a perspective view of a clog-reducing tip of a cuttingassembly of the surgical instrument of FIGS. 1 and 2 in accordance withan exemplary embodiment of the present disclosure.

FIG. 4 is a fragmentary elevational view of the clog-reducing tip of thecutting assembly of FIG. 3 with removed material representedschematically.

FIG. 5 is another fragmentary elevational view of the clog-reducing tipof the cutting assembly of FIG. 3.

FIG. 6 is another fragmentary elevational view of the clog-reducing tipof the cutting assembly of FIG. 3.

FIG. 7 a cross-sectional view of the cutting assembly of FIG. 3 takenalong lines 7-7.

FIG. 8 is a perspective view of the clog-reducing tip according toanother exemplary embodiment of the present disclosure.

FIG. 9 is fragmentary perspective view of the clog-reducing tip of FIG.8.

FIG. 10 is a perspective view of the clog-reducing tip according toanother exemplary embodiment of the present disclosure.

FIG. 11 is fragmentary perspective view of the clog-reducing tip of FIG.10.

FIG. 12 is a perspective view of the clog-reducing tip according toanother exemplary embodiment of the present disclosure.

FIG. 13 is elevational view of the clog-reducing tip of FIG. 12.

FIG. 14 is an angled view of the clog-reducing tip of FIG. 12.

FIG. 15 is a plan view of the clog-reducing tip of FIG. 12.

FIGS. 16-19 are diagrammatic views illustrating a machined process forforming the clog-reducing tip of FIGS. 12-15.

FIG. 20 is a cross-sectional view of the surgical instrument of FIG. 1taken along lines 20-20.

DETAILED DESCRIPTION

Referring to FIG. 1, one embodiment of a surgical instrument 10,according to the present disclosure, is shown for use in a medicalprocedure for a patient (not shown). In one embodiment, the surgicalinstrument 10 is an ENT shaver that is disposable and used for resectingsinus bone and tissue during endoscopic sinus surgery. As illustrated,the surgical instrument 10 includes a drive assembly, generallyindicated at 12 and shown in phantom lines, and a cutting assembly,generally indicated at 14, removably coupled to the drive assembly 12.The drive assembly 12 is used to rotate a portion of the cuttingassembly 14 to remove tissue, bone, etc. from a surgical site of thepatient. It should be appreciated that the surgical instrument 10 may beoperated by a user (not shown) such as a surgeon.

As illustrated in FIG. 1, the drive assembly 12 includes a housing 15extending axially. The housing 15 is generally cylindrical in shape. Thedrive assembly 12 also includes a motor 16 disposed in the housing 15and having a rotatable drive element 18 coupled to the cutting assembly14. The motor 16 may be of an electric or pneumatic type. In oneembodiment, the drive element 18 is removably coupled to the cuttingassembly 14.

It should be appreciated that, in one embodiment, the cutting assembly14 may be free of any motor. Thus, the cutting assembly 14 may beconfigured to be disposable after a single-use, or series of uses.Because the cutting assembly 14 may not include any motors, the cost ofthe cutting assembly 14 may be reduced.

Referring to FIGS. 1-7, the cutting assembly 14 includes a plurality oftubes or tube assembly, generally indicated at 20, extending axiallybetween a distal end 23 and a proximal end 21 (FIG. 20) opposite thedistal end 23. The tube assembly 20 has a longitudinal axis 24 definedbetween the proximal end 21 and the distal end 23. The tube assembly 20includes a window 22, for example, a cutting window, near or at thedistal end 23 with the window 22 adapted to be applied to a surgicalsite of a patient. In certain embodiments, the tube assembly 20 includesa first, or outer, tube 26 and a second, or inner, tube 28. The innertube 28 is coupled to the drive assembly 102 and rotatable by the driveelement 18 relative to the outer tube 26. The inner tube 28 may beremovably coupled to the drive element 18, for example, in an embodimentwhere the cutting assembly 14 is disposable after a single-use or seriesof uses.

In one embodiment, the outer tube 26 is non-rotatable and the inner tube28 is rotatable relative to the outer tube 26. The inner tube 28 and hasa lumen 30 extending between the proximal end 21 and the distal end 23of the tube assembly 20. The inner tube 28 may comprise a proximalregion 32 and a distal region 34 to be described. The inner tube 28comprises, forms, or defines a first or inner cutting window 36 at ornear the distal end 23 of the tube assembly 20, such as within thedistal region 34 of the inner tube 28.

Each of the inner tube 28 and the outer tube 26 may be generally hollowcylinders extending axially and have a generally circularcross-sectional shape. The outer tube 26 has a diameter greater than adiameter of the inner tube 28 such that the inner tube 28 is disposedwithin the outer tube 26. In other words, the outer tube 26 has a lumenextending between the proximal end 21 and the distal end 23 of the tubeassembly 20 with the inner tube 28 at least partially disposed withinthe lumen of the outer tube 26. In one embodiment to be described (seeFIG. 20), the inner tube 28 has an axial length longer than an axiallength of the outer tube 26 such that the inner tube 28 extends past aproximal region 38 of the outer tube 26 when the inner tube 28 isdisposed within the outer tube 26.

The outer tube 26 may comprise the proximal region 38 and a distalregion 40 as shown in FIG. 2. The outer tube 26 forms a second or outercutting window 42 at or near the distal end 23 of the tube assembly,such as within the distal region 40 of the outer tube 26. The innercutting window 36 and the outer cutting window 42 define the cuttingwindow 22 of the tube assembly 20. In one exemplary embodiment, theouter tube 26 may include a radial reduction step 44 within the distalregion 34 to allow an outer surface of the inner tube 28 and an innersurface of the outer tube 26 to be close together.

In one embodiment, the tube assembly 20 may further include anon-rotatable sheath or third or covering tube 46 disposed over aportion of the outer tube 26. The covering tube 46 has an axial lengthless than an axial length of the outer tube 26. The covering tube 46 maybe angled, straight, or malleable. It should be appreciated that thecovering tube 46 is optional. In addition, it should be appreciated thatthe covering tube 46 is coupled to a connecting hub 68 to be described.Furthermore, it should be appreciated that any suitable tubingconfiguration may be utilized so long as the cutting assembly 14 definesthe cutting window 22 and can be driven by the drive assembly 12.

The inner tube 28 and outer tube 26 are made of a metal material such asstainless steel or a non-metallic material such as a composite dependingon the application. The covering tube 46 may be made of a metal materialor a non-metallic material such as a composite depending on theapplication. It should be appreciated that a wall thickness of the innertube 28 and the outer tube 26 is relatively thin such as approximately0.1 to approximately 0.5 millimeters (mm) to allow the tube assembly 20to be of a relatively small diameter and also to be lightweight. Itshould also be appreciated that the diameters of the inner tube 28 andthe outer tube 26 have a relatively small diameter such as approximately2.0 mm to approximately 5.0 mm so as to work in a small opening of anasal cavity or oral cavity of the patient and to prevent the user'sview from being obstructed. In one embodiment, the tube assembly 20 mayhave a bend (not shown) near the distal end 23. It should further beappreciated that the inner tube 28 and the outer tube 26 may be scaledlarger or smaller depending on the application.

The cutting assembly 14 also includes a drive hub, generally indicatedat 48, disposed about a proximal end of the inner tube 28 to allow theinner tube 28 to be connected to the drive element 18 for rotation ofthe inner tube 28 about the longitudinal axis 24. The drive hub 48includes a hub member 50 disposed about the inner tube 28. The hubmember 50 extends axially and is generally cylindrical in shape. The hubmember 50 has an aperture 52 extending axially at least partiallytherethrough to receive the inner tube 28 as illustrated in FIG. 2. Thehub member 50 may also include a plurality of ridges 54 extendingradially and axially and spaced circumferentially thereabout. The hubmember 50 may further include a reduced diameter portion 56 adjacent theridges 54. The reduced diameter portion 56 of the hub member 50 definesa reduced aperture 53 in communication with the aperture 52 with thereduced aperture 53 being smaller in diameter than the aperture 52 (seeFIG. 20). The decrease in diameter from the aperture 52 to the reducedaperture 53 forms a lip 55 adapted to be positioned adjacent to or in anabutting relationship with the proximal end 21 of the tube assembly 20in a manner to be described. The hub member 50 also includes a flange 58extending radially at a distal end thereof. The hub member 50 may bemade of a non-metallic material. The hub member 50 may be integral,unitary, and formed as one-piece.

The drive hub 48 can also include a spring 60 and a seal 62 such as ano-ring disposed about the hub member 50 at a proximal end thereof in thereduced diameter portion 56. The drive hub 48 may include a washer 64and a seal 66 such as an o-ring at a distal end thereof disposed aboutthe distal end of the inner tube 28. It should be appreciated that thedrive hub 48 allows for rotation of the inner tube 28 and may allow forthe transfer of fluid through the inner tube 28. It should also beappreciated that a variety of drive coupling configurations may be usedwith the cutting assembly 14.

The cutting assembly 14 further includes a connecting hub, generallyindicated at 68, disposed about the inner tube 28 and a portion of thedrive hub 50 to allow the drive assembly 12 to be removably coupled tothe cutting assembly 14. The connecting hub 68 includes a housing hub 70adapted to be engaged by a least a portion of a hand of a user andsupporting the outer tube 26 or the covering tube 46. The housing hub 70includes an aperture 72 extending axially therethrough to receive theouter tube 26 or the covering tube 46. The housing hub 70 may include aplurality of grip members 74 extending radially and axially and a flange76 extending radially outwardly at one end to support one or morefingers of a hand. The connecting hub 68 also includes a coupling member78 disposed about the inner tube 28. The coupling member 78 extendsaxially and is generally cylindrical in shape. The coupling member 70has an aperture 72 extending axially therethrough to receive the innertube 28. The coupling member 78 includes a cavity 80 extending axiallyinto the proximal end thereof to receive a distal end of the fluidcoupling. The coupling member 78 may include one or more ridges 82extending radially and spaced circumferentially from each other at theproximal end to be coupled to the housing 15 of the drive assembly 12.The coupling member 78 may include one or more grooves 84 extendingradially inward and circumferentially and spaced axially from each otherand one or more seals 86 such as o-rings disposed in the grooves 84. Theconnecting hub 68 is made of a non-metallic material. The connecting hub68 may be integral, unitary, and formed as one-piece. It should beappreciated that the connecting hub 68 allows for the coupling of thedrive assembly 12 to the cutting assembly 14.

Referring to FIG. 3, the cutting window 22 includes the inner cuttingwindow 36 in the inner tube 28 formed as an opening extending axiallyand diametrically through a wall on one side near the distal end 23 ofthe tube assembly 20. The cutting window 22 also includes the outercutting window 42 in the outer tube 26 formed as an opening extendingaxially and diametrically through a wall on one side near the distal end23 of the tube assembly 20. The inner and outer cutting windows 36 and42 are generally elongated and oval in shape, but may be any suitableshape. The inner cutting window 36 may include at least one or morecutting edges 90. The cutting edge 90 may include a plurality of teeth92 forming a serrated edge. The outer cutting window 42 may include atleast one or more cutting edges 94. The cutting edge 94 may include aplurality of teeth 92 forming a serrated edge. The inner cutting window36 is adapted to be temporarily aligned radially with the outer cuttingwindow 42 to receive material within the cutting window 22 as the innertube 28 rotates within the outer tube 26. As the inner tube 28 rotateswithin the outer tube 26, the inner and outer cutting windows 36 and 42are removed from radial alignment such that the cutting edges 90 and 94cut or reduce the material positioned within the cutting window 22 ofthe tube assembly 20.

In one embodiment illustrated in FIG. 1, the surgical instrument 10includes an irrigation connection 95 on the housing 15 for connection toa fluid source and an irrigation path or passage 96 extending throughthe housing 15 between the irrigation connection 95 and the cuttingassembly 14 and between the inner tube 28 and the outer tube 26 to thewindow 22 to provide lubrication. The surgical instrument 10 alsoincludes an aspiration or suction connection 97 on the housing 15 forconnection to a suction source and an aspiration or suction path orpassage 98 extending through the housing 15 between the suctionconnection 97 and the first cutting window 36 of the inner tube 28.

FIGS. 4-6 show fragmentary elevational views of a clog-reducing tip,generally indicated at 104, in accordance with an exemplary embodimentof the present disclosure. Referring first to FIG. 4, the cutting window22 of the tube assembly 20 comprises a distal boundary 103 and aproximal boundary 101 opposite the distal boundary 103. In oneembodiment, the boundaries 101 and 103 may be defined as an imaginaryplane extending perpendicularly to the longitudinal axis 24 of the tubeassembly 20 at a proximal-most point and a distal-most point of thecutting window 22, respectively. Thus, in the exemplary embodimentillustrated in FIG. 4, the outer tube 26 projects distal to the innertube 28 to define the proximal boundary 101 of the cutting window 22,and the distal end 23 the inner tube 28 is positioned proximally (i.e.,within) the outer tube 26 to define the distal boundary 103 of thecutting window 22. Stated differently, the proximal and distalboundaries 101 and 103 may be considered the proximal-most anddistal-most points of the cutting window 22, respectively, when thecutting window 22 is viewed in plan. In certain embodiments, a portionof the inner tube 28 distal to the proximal boundary 101 of the cuttingwindow 22 defines the distal region 34 of the inner tube 28.

As illustrated in FIG. 4, the clog-reducing tip 104 of the tube assembly20 comprises a projection 112 within the lumen 30 of the inner tube 28.The projection 112 is adapted to reduce the size of material removablethrough the cutting window 22, thereby reducing clogging of the tubeassembly 20. In certain embodiments, at least a portion of theprojection 112 is positioned distal to the proximal boundary 101 (in adirection of arrow 102 in FIG. 4) to provide a reduced cross sectionalarea to said lumen 30 relative to the cross sectional area of the lumen30 proximal to the projection 112. For another example, the projection112 occupies a volume V₁₁₂ (FIG. 5) within the distal region 34 of theinner tube 28. The projection 112 reduces the amount by which material106 to be removed may penetrate the cutting window 22. Consequently, thecutting action from rotating the inner tube 28 within the outer tube 26(via the cutting edges 90 and 94) reduces the material 106 intosufficiently small bits before the material 106 may pass within thelumen 30 proximal to the cutting window 22, thereby decreasing thelikelihood of clogging of the tube assembly 20.

In certain embodiments, the reduced cross sectional area of the lumen 30may defined as the difference between the cross sectional area of thelumen 30 (e.g., π*d with d being the diameter of the lumen 30) and across sectional area of the projection 112. In one example, a ratio ofthe reduced cross sectional area of the lumen 30 to the cross sectionalarea of the lumen 30 is within the range of 1:1.1 to 1:2.0, and moreparticularly within the range 1:1.3 to 1:1.8, and even more particularlywithin the range of 1:1.5 to 1:1.6. The reduced cross sectional isadapted to ensure that no dimension of material 106 (e.g., bone and/ortissue chip) is larger than the cross sectional area of the lumen 30,and more particularly less than the cross sectional area of the lumen 30by a predetermined factor based on the ratio described above. In otherexemplary embodiments, the volume V₁₁₂ of the projection 112 disposedwithin the distal region 34 occupies within the range of 10%-70% of avolume V₂₀ of the distal region 34 of the tube assembly 20, and moreparticularly within the range of 20%-60% of the volume V₂₀ of the distalregion 34 (see FIG. 5).

In one exemplary operation of a conventional ENT shaver, the material isable to penetrate the cutting window to contact the inner tube oppositethe cutting window such that the size of the reduced material isapproximately equal to the diameter of the lumen. The reduced materialhaving a size approximately equal to the diameter of the lumen increasesthe likelihood of the reduced material clogging within the lumen,particularly near the cutting window. Furthermore, in instances wherethe axial length of the cutting window is greater than the diameter ofthe lumen, the likelihood of the reduced material clogging is furtherincreased in conventional ENT shavers.

The clog-reducing tip 104 of the present disclosure significantlyreduces the likelihood of clogging by, for example, providing that thedistance from the proximal boundary 101 of the cutting window 22 at theouter tube 26 to a nearest point on the projection 112 (approximated aspoint 105 as shown in FIG. 4) is less than the diameter of the lumen 30.Thus, any reduced material 106 that may pass through the “throat” (i.e.,the distance from cutting window 22 to the nearest point 105) has a sizesmaller than the diameter of the lumen 30 itself. Consequently, once thereduced material reaches the lumen 30 proximal to the projection 112, itis increasingly unlikely that the reduced material clogs the tubeassembly 20.

Prior to the material being sufficiently reduced to pass through the“throat” of the inner tube 28, the projection 112 (and the proximalboundary 101 of the cutting window 22) maintains the material 106 in aposition such that the cutting action continues to reduce the material106 with each rotation of the inner tube 28. Despite the material 106possibly remaining positioned near the cutting window 22 for increasedtime, empirical investigations have shown minimal effect on materialremoval capacity of the tube assembly 20 incorporating the clog-reducingtip 104 with near or total elimination of clogging commonly associatedwith conventional ENT shavers.

With continued reference to FIG. 4 and concurrent reference to FIG. 6,the projection 112 may extend within the lumen 30 from near the distalend 23 of the tube assembly 20 to a position proximal to (i.e., in thedirection of arrow 100) the proximal boundary 101. In other words,another portion 113 of the projection 112 may be positioned proximal tothe proximal boundary 101. In other words, the axial length L₁₁₂ of theprojection 112 may be greater than the axial length L₂₂ of the cuttingwindow 22. Positioning the portion 113 of the projection 112 proximal tothe proximal boundary 101 ensures that the material 106 passing throughthe proximal boundary 101 is reduced to a size less than the crosssectional area of the lumen 30 of the tube assembly 20. It is understoodthat the axial length L₁₁₂ of the projection 112 may be greater than anaxial length L₄₂ of the outer cutting window 42 and/or less than anaxial length L₃₆ of the inner cutting window 36. In certain embodiments,the projection 112 may extend even more proximally to the proximalboundary 101 than shown in FIGS. 4 and 6 with a proximal second portion110 b to be described having a shallower taper.

The projection 112 of the clog-reducing tip 104 has a shelf or an innersurface 110. The inner surface 110 is displaced radially inward relativeto an interior surface 108 of the lumen 30 (i.e., proximal to theprojection 112) towards the longitudinal axis 24 of the tube assembly20. Referring to FIG. 5, the projection 112 may be angled relative tothe interior surface 108 of the lumen 30. For example, a line extendingbetween distal and proximal ends of the projection 112 may be orientedat an angle α in the range of approximately 5 degrees to approximately40 degrees relative to the interior surface 108 of the lumen 30. Inother embodiments, the angle α is between approximately 10 degrees andapproximately 30 degrees, and more particularly between approximately 15degrees and approximately 25 degrees. The angle α generally provides aprofile (when viewed in elevation as shown in FIGS. 4-6) to theprojection 112 that tapers in the direction of arrow 100. In otherwords, a distance from the longitudinal axis 24 to the projection 112 atthe distal boundary 103 of the cutting window 22 is less than a distancefrom the longitudinal axis 24 from the projection 112 at the proximalboundary 101 of the cutting window 22 such that the projection 112tapers in the direction towards the proximal boundary 101. The taperingof the projection 112 advantageously maintains the material 106 near thedistal boundary 103 closer to the cutting edges 90 and 94 to reduces thematerial 106 into smaller bits as the reduced material 106 moves alongthe inner surface 110 of the projection 112 towards the lumen 30proximal to the cutting window 22. The tapering of the projection 112also ensures a gradual transition through the “throat,” as previouslydescribed, such that reduced material 106 passing through the “throat”immediately encounters a greater cross sectional area of the lumen 30and is quickly urged proximally within the lumen 30 under forces fromthe suction source.

In certain embodiments, the inner surface 110 of the projection 112further comprises or is defined by a distal first portion 110 a and theproximal second portion 110 b proximal to the distal first portion 110a. Referring to FIGS. 5 and 6. The distal first portion 110 a may beoriented substantially parallel to the longitudinal axis 24 of the tubeassembly 20. The distal first portion 110 a may be substantially planarwhen viewed in elevation. The proximal second portion 110 b may besloped or angled relative to the distal first portion 110 a and theinterior surface 108 of the lumen 30. The proximal second portion 110 bmay be arcuate when viewed in elevation to provide a smooth transitionto the distal first portion 110 a. The proximal second portion 110 b maybe oriented at an angle β in the range of approximately 20 degrees toapproximately 60 degrees relative to the interior surface 108 of thelumen 30. In other embodiments, the angle β is between approximately 30degrees and approximately 50 degrees.

Referring to FIG. 7, the projection 112 may be positioned about thelongitudinal axis 24 radially opposite the cutting window 22 of the tubeassembly 20, and more particularly radially opposite the inner cuttingwindow 36. With the projection 112 within the lumen 30 of the inner tube28, the relative positioning between the projection 112 and the innercutting window 36 remains constant as the inner tube 28 rotates withinthe outer tube 26. The radial position of the cutting window 22 of FIG.7 is approximated between lines W1 and W2 with the projection 112 beingpositioned about the longitudinal axis 24 substantially opposite thespace between lines W1 and W2.

The projection 112 is positioned about a circumference of the lumen 30in a manner sufficient to suitably reduce the material 106 to preventclogging of the tube assembly 20. In certain embodiments, the projection112 is positioned about less than one half of the circumference of thelumen 30. For example, the axial cross sectional view FIG. 7 shows oneside of the projection 112 radially positioned approximately at the 4o'clock position, and another side of the projection 112 radiallypositioned approximately at the 8 o'clock position. Stated differently,an angle γ about the longitudinal axis 24 and extending between opposingsides of the projection 112 within the range of approximately 70 degreesto approximately 180 degrees, and more particularly with the range ofapproximately 90 degrees to approximately 160 degrees, and even moreparticularly with the range of approximately 110 degrees toapproximately 150 degrees. Other suitable values for the angle γ arecontemplated based on, at least in part, the diameter of the lumen 30,the intended application of the surgical instrument 10, and the like.

In certain embodiments, the clog-reducing tip 104 includes an insertsecured within the lumen 30 of the inner tube 28. The insert defines theprojection 112 and forms the inner surface 110. For example, the insertmay be bonded to the lumen 30 of the inner tube 28. The insert mayinclude an outer surface 111 and the inner surface 110 with the outersurface 111 shaped to conform a portion of the lumen 30 (see FIG. 7).The inner surface 110 may define the projection 112. The insert may havea thickness defined between the inner surface 110 and the outer surface111 with the thickness of the insert tapering in an axial direction;i.e., the direction 100 towards the proximal boundary 101 of the cuttingwindow 22. It is also understood that the thickness of the insert maytaper radially about the longitudinal axis 24 of the tube assembly 20,as shown in FIG. 7.

In another exemplary embodiment of the clog-reducing tip 104 illustratedin FIGS. 10 and 11, the projection 112 is defined by the lumen 30 distalto the proximal boundary 101 being formed radially inwardly towards thelongitudinal axis 24. In other words, whereas the projection 112 ofFIGS. 4-6 are within the lumen 30 with the inner tube 28 having agenerally cylindrical outer profile to the distal end 23 of the tubeassembly 20, the FIGS. 10 and 11 show the inner tube 28 near the distalend 23 (e.g., the distal region 34) deformed inwardly towards thelongitudinal axis 24. With a portion of the inner tube 28 deformedinwardly, the lumen 30 of the inner tube 28 is corresponding deformedinwardly and consequently defines the projection 112 providing thereduced cross sectional area of the lumen 30 as previously described.The inwardly deformed portion of the inner tube 28 may be constructedthrough stamping, drawing, or similarly suitable manufacturing process.

Referring to FIGS. 12-15, yet another embodiment, according to thepresent disclosure, of the clog-reducing tip 104 is shown. In thisembodiment, the clog-reducing tip 104 includes the inner surface 110formed by boring out an eccentric borehole within the distal region 34of the inner tube 28. The borehole is eccentric with respect to thelongitudinal axis 24 of the tube assembly 24. The eccentric borehole isin communication with the cutting window 22 and the lumen 30 of theinner tube 28. This type of tip would typically be machined. Asillustrated, the inner surface 110 has a smaller cross-section at thefirst cutting window 36. The process of machining the clog-reducing tip104 is illustrated in FIGS. 16-19.

The present disclosure provides a method, according to one embodiment ofthe present disclosure, for operating the surgical instrument 10 on apatient. The method includes the steps of providing the cutting assembly14 including the tube assembly 20 extending axially. The tube assembly20 includes the rotatable inner tube 28 having the lumen 30 disposedcoaxially within the outer tube 26. The inner tube 28 forms the innercutting window 36, and the outer tube 26 forms the outer cutting window42. The inner and outer cutting windows 36, 42 define the cutting window22 of the tube assembly 20. The method may also include the steps ofproviding the projection 112 within the lumen 30 of the inner tube 28with at least a portion of the projection 112 disposed within the distalregion 34 of the inner tube 28 with the projection 112. In certainembodiments, the projection 112 positioned distal to the proximalboundary 101 of the cutting window 22. The projection 112 provides areduced cross sectional area to the inner tube 28 relative to a crosssectional area of the lumen proximal to the projection 112. In certainembodiments, the projection 112 is the volume V₁₁₂ that occupies thevolume V₂₀ of the lumen 30 distal to the proximal boundary 101 of thecutting window 22. The method includes the step of applying the cuttingwindow to a surgical site of a patient and rotating the inner tube 28relative to the outer tube 26 by the drive assembly 12 to cut thematerial 106 by an interaction of the inner cutting window 36 and theouter cutting window 42 on the patient, wherein the projection 112reduces the size of the material 106 removed through the cutting window22 to reduce clogging of the tube assembly 20.

The surgical instrument 10 of the present disclosure also advantageouslyreduces the likelihood of clogging at or just proximal to the tubeassembly 20 of the surgical instrument 10. FIG. 20 is a cross sectionalview of a portion of the surgical instrument of FIG. 1, showing inparticular an interface 114 between the tube assembly 20 and the drivehub 48. As mentioned, the hub member 50 of the drive hub 48 includes thereduced diameter portion 56 defining the reduced aperture 53 incommunication with the aperture 52 of the drive hub 48 (and theconnecting hub 68). The lip 55 is formed by the decrease in diameterfrom the aperture 52 to the reduced aperture 53. The inner tube 28 hasan axial length longer than an axial length of the outer tube 26 suchthat the inner tube 28 extends past the proximal region 38 of the outertube 26 and into the connecting hub 68 and the drive hub 48, as shown inFIG. 20.

During assembly of the surgical instrument 10, such as when coupling thetube assembly 20 with the drive hub 48, the inner tube 28 is slidablyinserted within the aperture 52 of the drive hub 48 and positionedadjacent or in an abutting relationship with the lip 55. The lip 55facilitates appropriate axial positioning the tube assembly 20 relativeto the housing 15 and other structures of the surgical instrument 10.The lumen 30 of the inner tube 28 is in fluid communication with thereduced aperture 53 of the drive hub 48, as shown in FIG. 20, such thatreduced material 106 may pass from the lumen 30 to the suction source.

The diameter of the lumen 30 of the inner tube 28 is less than thediameter of the reduced aperture 53 at the interface 114. In otherwords, the reduced material 106 moves from a smaller cross sectionalarea of the lumen 30 to a greater cross sectional area of the reducedaperture 53 as the material 106 passes through the interface 114. Ineffect, the passage through which the reduced material is movingexpands, thereby reducing the likelihood of clogging. If, for acontrasting example, the diameter of the lumen 30 of the inner tube 28was greater than the diameter of the reduced aperture 53, the reducedmaterial 106 may become lodged on the lip 55 and increase the likelihoodof clogging at the interface 114.

Thus, according to one exemplary embodiment of the present disclosure, acutting assembly for a surgical instrument having a drive assembly, saidcutting assembly comprising: a tube assembly comprising a cutting windownear a distal end and adapted to be applied to a surgical site of apatient, an outer tube, an inner tube coaxially disposed within androtatable relative to said outer tube with the drive assembly with saidinner tube comprising a lumen; and a drive hub coupled to said innertube with said drive hub defining an aperture adapted to slidablyreceive a proximal end of said inner tube, and defining a reducedaperture in communication with said aperture, wherein a diameter of saidreduced aperture is less than a diameter of said aperture, wherein adiameter of said lumen is less than said diameter of said reducedaperture when said proximal end of said inner tube is slidably receivedwithin said aperture to reduce clogging of said surgical instrument asremoved material moves from said lumen to said reduced aperture of saiddrive hub. A lip is formed at an interface between said aperture andsaid reduced aperture with said proximal end of said inner tube adaptedto be positioned adjacent to said lip.

Accordingly, the surgical instrument 10 of the present disclosurereduces the occurrence of the clogging by providing the clog-reducingtip 104 having the projection 112 for reducing a cross sectional area ofthe lumen 30 distal to the proximal boundary 101 of the cutting window22 and/or for providing the volume V₁₁₂ within the volume V₂₀ of thedistal region 34 of the tube assembly 20. The size of the material 106that may enter the distal region 34 of the inner tube 28 is limited andmaintained in a position to be further reduced by the cutting action.Further, only material 106 of sufficiently reduced sized may passthrough the “throat” of the tube assembly 20, after which the reducedmaterial 106 encounters the larger cross sectional of the lumen 30 alsounder the influence of suction. The projection 112 may be the insertsecured with the lumen 30 of the inner tube 28, or formed integrallywith the same, such as by deforming the distal region 34 of the innertube 28, providing the borehole eccentric to the longitudinal axis 24 ofthe tube assembly 24, or suitably milling within the inner tube 28 todefine the projection 112. The surgical instrument 10 of the presentdisclosure cuts and aspirates tissue as per current shaver systemsutilizing suction. It should be appreciated that, in another embodiment,the surgical instrument 10 may be used with the surgical tools or be adedicated tool or instrument.

It will be further appreciated that the terms “include,” “includes,” and“including” have the same meaning as the terms “comprise,” “comprises,”and “comprising.”

The present invention has been described in an illustrative manner. Itis to be understood that the terminology, which has been used, isintended to be in the nature of words of description rather than oflimitation. Many modifications and variations of the present inventionare possible in light of the above teachings. Therefore, the presentinvention may be practiced other than as specifically described.

Embodiments of the disclosure may be described with reference to thefollowing exemplary clauses:

Clause 1—A cutting assembly for a surgical instrument for cuttingtissue, said cutting assembly being configured to be coupled to a driveassembly including a motor having a rotatable drive element enclosed ina housing and said cutting assembly comprising: a rotatable first tubehaving a lumen, said lumen having a proximal region and a distal region,said first tube forming a first cutting window in said distal region; asecond tube disposed over said first tube, said second tube having aproximal region and a distal region, said second tube forming a secondcutting window in said distal region; said first tube being rotatablerelative to said second tube; said proximal region of said window ofsaid lumen having a cross-sectional area greater than a cross-sectionalarea of said distal region of said lumen such that tissue cut by aninteraction of said first cutting window and said second cutting windowis of suitable dimensions to allow passage through said first cuttingwindow and said distal region of said lumen to said proximal region ofsaid lumen to prevent clogging of said distal region of said lumen.

Clause 2—A cutting assembly as set forth in clause 1 wherein saidproximal region of said lumen has an interior surface and said distalregion of said lumen has an inner surface opposite said first cuttingwindow.

Clause 3—A cutting assembly as set forth in clause 2 wherein said innersurface is displaced radially inward relative to said interior surface.

Clause 4—A cutting assembly as set forth in clause 2 wherein said innersurface extends radially and axially at an angle greater than zerorelative to said interior surface.

Clause 5—A cutting assembly as set forth in clause 2 including an insertdisposed within said distal region of said lumen opposite said firstcutting window and forming said inner surface.

Clause 6—A cutting assembly as set forth in clause 5 wherein said insertis bonded to said first tube.

Clause 7—A cutting assembly as set forth in clause 5 wherein said insertincludes said inner surface extending radially and axially at an anglegreater than zero relative to said interior surface.

Clause 8—A cutting assembly as set forth in clause 5 wherein said inserthas one of a generally arcuate, semi-circular, and rectangularcross-sectional profile.

Clause 9—A cutting assembly as set forth in clause 5 wherein said insertis made of one or more different materials.

Clause 10—A cutting assembly as set forth in clause 2 wherein said innersurface is defined by said inner tube in said distal region of saidlumen opposite said first cutting window.

Clause 11—A cutting assembly as set forth in clause 2 wherein said innersurface extends axially from a distal end of said distal region of saidlumen to one of less than and at least a proximal end of said firstcutting window.

Clause 12—A cutting assembly as set forth in clause 11 wherein saidfirst cutting window has an axial length less than an axial length ofone of said inner surface and said second cutting window.

Clause 13—A cutting assembly as set forth in clause 11 wherein an angleof said inner surface to a tube wall of said distal region of said lumenis between approximately 20 degrees and approximately 90 degrees.

Clause 14—A cutting assembly as set forth in clause 11 wherein saidinner surface has a radial height greater than a radial height of saidinterior surface.

Clause 15—A cutting assembly as set forth in clause 1 including a thirdtube disposed over said second tube.

Clause 16—A cutting assembly as set forth in clause 1 wherein saiddistal region of said lumen has a profile formed by one of a drawingprocess and a machined process.

Clause 17—A cutting assembly as set forth in clause 16 wherein saiddistal region of said lumen has a non-circular cross-section.

Clause 18—A cutting assembly as set forth in clause 1 wherein said firstcutting window includes at least one cutting edge.

Clause 19—A cutting assembly as set forth in clause 1 including anaspiration path connected to either one of said first tube and saidsecond tube.

Clause 20—A cutting assembly as set forth in clause 1 wherein across-section of said distal region of said lumen and a cross-section ofsaid proximal region of said lumen has a ratio of one of 1:1.5, 1:3, and1:6.

Clause 21—A cutting assembly as set forth in clause 1 wherein an axiallength of said first cutting window relative to a diameter of saiddistal region of said lumen is such that no dimension of a bone chipthat is cut is larger than a diameter of said lumen in said proximalregion.

Clause 22—A surgical instrument for use on a patient, said surgicalinstrument comprising: a cutting assembly including a plurality of tubesextending axially, said tubes comprising at least a rotatable inner tubehaving a lumen, said lumen having a proximal region and a distal region,said inner tube forming an inner cutting window in said distal region,an outer tube disposed over said inner tube, said outer tube having aproximal region and a distal region, said outer tube forming an outercutting window in said distal region, said inner tube being rotatablerelative to said outer tube; a drive assembly including a motor having arotatable drive element, a housing for enclosing said motor and beingremovably coupled to said cutting assembly, a suction connection on saidhousing for connection to a suction source, and a suction passageextending from said inner window through said inner tube and throughsaid housing to said suction connection; an irrigation connection onsaid housing for connection to a fluid source; an irrigation passageextending through said housing between said irrigation connection andsaid cutting assembly and between said inner tube and said outer tube tosaid cutting window to provide lubrication and flush blood, tissue, andbone; a suction connection on said housing for connection to a suctionsource; a suction passage extending through said housing between saidsuction connection and said cutting window of said inner tube; and saidproximal region of said lumen having a cross-sectional area greater thana cross-sectional area of said distal region of said lumen such thattissue cut by an interaction of said inner cutting window and said outercutting window of suitable dimensions to allow passage through saidinner cutting window and said distal region of said lumen to saidproximal region of said lumen to prevent clogging of said distal regionof said lumen.

Clause 23—A method of operating a surgical instrument for use on apatient, said method comprising the steps of: providing a cuttingassembly including a plurality of tubes extending axially, the tubescomprising at least a rotatable inner tube having a lumen, the lumenhaving a proximal region and a distal region, the inner tube forming aninner cutting window in the distal region, an outer tube disposed overthe inner tube, the outer tube having a proximal region and a distalregion, the outer tube forming an outer cutting window in said distalregion, the inner tube being rotatable relative to the outer tube;providing a drive assembly including a motor having a rotatable driveelement, a housing for enclosing the motor and being removably coupledto the cutting assembly, a suction connection on the housing forconnection to a suction source, and a suction passage extending from theinner window through the inner tube and through the housing to thesuction connection; providing the proximal region of the lumen having across-sectional area greater than a cross-sectional area of the distalregion of the lumen; rotating the inner tube relative to the outer tubeby the drive assembly; cutting bone and/or tissue by an interaction ofthe inner cutting window and the outer cutting window on the patient;and allowing passage of cut bone and/or tissue of suitable dimensionsthrough the inner cutting window and the distal region of the lumen tothe proximal region of the lumen to prevent clogging of the distalregion of the lumen.

Clause 24—A surgical instrument, cutting assembly, and method asdisclosed and described herein, including equivalents not specificallyrecited herein.

What is claimed is:
 1. A cutting assembly for a surgical instrumenthaving a drive assembly, said cutting assembly comprising: a tubeassembly comprising a longitudinal axis extending proximally from adistal end opposite a proximal end, and a cutting window near saiddistal end and adapted to be applied to a surgical site of a patientwith said cutting window comprising a distal boundary opposite aproximal boundary, said tube assembly further comprising; an outer tubecomprising an outer cutting window near said distal end of said tubeassembly; an inner tube coaxially disposed within and rotatable relativeto said outer tube with the drive assembly, said inner tube comprisingan inner cutting window near said distal end and a lumen extendingbetween said proximal end and said inner cutting window with said innercutting window and said outer cutting window defining said cuttingwindow of said tube assembly; and a projection within said lumen of saidinner tube with at least a portion of said projection positioned distalto said proximal boundary of said cutting window, said projectionproviding a reduced cross sectional area to said lumen of said innertube relative to a cross sectional area of said lumen proximal to saidprojection with said reduced cross sectional area adapted to reduce asize of material removable through said cutting window to reduceclogging of said tube assembly.
 2. The cutting assembly of claim 1,further comprising an insert secured within said lumen of said innertube with said insert defining said projection providing said reducedcross sectional area.
 3. The cutting assembly of claim 2, wherein saidinsert comprises an outer surface and an inner surface opposite saidouter surface with said outer surface shaped to conform a portion ofsaid lumen and said inner surface defining said projection.
 4. Thecutting assembly of claim 3, wherein a thickness of said insert definedbetween said inner surface and said outer surface tapers in a directiontowards said proximal boundary of said cutting window.
 5. The cuttingassembly of claim 1, wherein said lumen of said inner tube distal saidproximal boundary of said cutting window is formed radially inwardlytowards said longitudinal axis to define said projection providing saidreduced cross sectional area.
 6. The cutting assembly of claim 1,wherein a ratio of said reduced cross sectional area of said inner tubeto said cross sectional area of said lumen is within a range of 1:1.3 to1:1.8.
 7. The cutting assembly of claim 1, wherein another portion ofsaid projection is positioned proximal to said proximal boundary of saidcutting window.
 8. The cutting assembly of claim 1, wherein saidprojection is positioned about said longitudinal axis radially oppositesaid inner cutting window.
 9. The cutting assembly of claim 1, wherein adistance from said longitudinal axis to said projection at said distalboundary of said cutting window is less than a distance from saidlongitudinal axis from said projection at said proximate boundary ofsaid cutting window such that said projection tapers in a directiontowards said proximal boundary.
 10. The cutting assembly of claim 1,wherein said projection is further defined by a distal first portioncomprising a substantially planar inner surface and a proximal secondportion proximal to said distal first portion with said proximal secondportion comprising an arcuate inner surface.
 11. The cutting assembly ofclaim 1, wherein a distance from said proximal boundary of said cuttingwindow at said outer tube to a nearest point on said projection is lessthan a diameter of said lumen of said inner tube such that the size ofthe reduced material passing to said lumen is at most equal to saiddistance that is less than said diameter of said lumen, thereby reducingclogging of said tube assembly.
 12. The cutting assembly of claim 1,wherein said projection is at least partially defined by a boreholewithin said inner tube and eccentric to said longitudinal axis with saideccentric borehole in communication with said cutting window and saidlumen.
 13. The cutting assembly of claim 1, wherein relative positioningbetween said projection and said inner cutting window remains constantas said inner tube rotates within said outer tube.
 14. A cuttingassembly for a surgical instrument having a drive assembly, said cuttingassembly comprising: a tube assembly comprising a longitudinal axisextending proximally from a distal end opposite a proximal end, and acutting window near said distal end and adapted to be applied to asurgical site of a patient, said cutting window comprising a distalboundary opposite a proximal boundary, said tube assembly furthercomprising: an outer tube comprising an outer cutting window within adistal region; an inner tube coaxially disposed within and rotatablerelative to said outer tube with the drive assembly, wherein a portionof said inner tube distal to said proximal boundary of said tubeassembly defines a distal region of said inner tube, said inner tubecomprising an inner cutting window within said distal region with saidinner cutting window and said outer cutting window defining said cuttingwindow of said tube assembly; and a projection within said inner tubewith at least a portion of said projection disposed within said distalregion of said inner tube with said projection adapted to reduce a sizeof removed material through said cutting window to reduce clogging ofsaid tube assembly.
 15. The cutting assembly of claim 14, wherein avolume of said projection disposed within said distal region of theinner tube occupies within a range of 20%-60% of a volume of said distalregion of said tube assembly.